1. Field of the Invention
This invention relates to the design and methods of manufacture of semiconductor integrated circuits for color camera chips as well as black-and-white camera chips in standard integrated circuit technology, and more particularly to MOSFET camera chips.
2. Description of Related Art
U.S. Pat. No. 5,350,490 of Lee for "Forming a Color Filter On A Semiconductor Substrate" describes a method of forming a color filter on an integrated circuit device for a Charge Coupled Device (CCD) or a Bucket Brigade Device (BBD) type of system.
U.S. Pat. No. 4,875,091 of Yamada et al for "Field-Sequential Color Imaging Apparatus" shows a rotary color filter for an imaging apparatus; and an electrical system for color imaging.
In contemporary designs, the photodiode in each detector cell is associated with a single transistor. Hence, both read signals and write signals to the photodiode share a single path. This causes excessive parasitic signals in the shared datapath which degrade performance.
There are problems with a system-level approach of achieving color sensitivity in photodiode arrays.
There are system-level designs which use several sets of photodiode-arrays with one for each color and discrete color filters and external gain-circuits, which is expensive. A performance problem with a system level circuit is that an error-correction function is required to account for the fact that the use of multiple discrete photodiode-arrays means that slightly different images fall on each array.